Wireless fixed and mobile communication systems keep evolving providing an ever increasing need for data bandwidth. To enable the delivery of increased data bandwidth the use of use of improved radio access and modulation schemes are being utilized. However RF spectrum is a limited resource and further improvements in modulation schemes will not solve the need for higher data bandwidths. Therefore Wireless fixed and mobile communication systems in order to provide improved data bandwidth may use multiple carriers for the transmission and/or reception of data.
Wireless communication is a virtual necessity in today's society as people increasingly use cordless phones, cellular phones, wireless data communication devices, and the like on a daily basis. The ability to communicate wirelessly has become pervasive in homes, businesses, retail establishments, and in the outdoors generally. Consequently, people can now communicate while in transit and in almost any environment.
Wireless communication involves the use of a limited resource: the electromagnetic spectrum. Different wireless communication schemes utilize different bands or segments of the electromagnetic spectrum in different manners. Typically, each particular segment of the electromagnetic spectrum is utilized in accordance with a wireless standard that has been created by a government entity, an industry consortium, and/or some other regulatory body.
There are many wireless standards under which wireless devices operate today. Example wireless standards include, but are not limited to, Bluetooth, Digital Enhanced Cordless Telecommunications (DECT), Code Division Multiple Access (CDMA)-2000, Wideband-CDMA (WCDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Wi-Fi, WiMAX, Long Term Evolution (LTE) and so forth.
A wireless communication device that operates in accordance with any one of these standards or another standard can generally receive and transmit electromagnetic signal waves that occupy a portion of the frequency spectrum. Wireless communication devices are generally designed to operate within a particular frequency band so as to avoid interfering with competing electromagnetic signal waves. Different frequency bands offer different advantages and disadvantages for wireless communication. For example, different frequency bands have different propagation and interference characteristics. Moreover, the various wireless standards, which generally correspond to an assigned frequency band or bands, provide for different propagation, interference-resistance, range, throughput, and other characteristics. Generally, no individual frequency band or wireless standard can be optimum for all communications in all situations.
Presently the current method for delivering data to a wireless edge device 101 is shown in FIG. 1 where a radio access node 102 transmits information downlink RF link 103 that uses a RF carrier 104 is able to communicate with the wireless edge device. Similarly the wireless edge device is able to communicate back to the radio access point 102 by means of an uplink RF link 105 using an uplink carrier 106. The uplink and downlink scheme depicted in FIG. 1 could be for Frequency Division Duplex (FDD) or Time Division Duplex (TDD) wireless fixed and or mobile communication systems.
With a multi carrier wireless system for fixed and or mobile communication systems data bandwidth made available for the wireless edge device to utilize can be increased. The amount of increased bandwith made available to the wireless edge device 101 can be increased by making many RF carriers 104, 106 available for the wireless edge device to utilize. For example when using the same radio access scheme and rf channel bandwidth increasing the amount of RF carriers from one to two, in FIG. 2, has the potential of doubling the overall bandwidth that the wireless edge device can utilize. The amount of RF carriers however does not need to be limited two or rely on the same radio access technology or RF bandwidth.
Additionally increasing the amount of RF carriers from one to two or N has the potential of increasing the available bandwidth for the wireless edge device by the amount of RF carriers. Therefore increasing the amount of RF carriers, FIG. 3, the wireless edge device can utilize will improve its potential data bandwidth capabilities as long as it is matched with the appropriate rf access points capability.
Further, the use of multiple carriers may be used in combination with multiple-input multiple-output (MIMO).
However the multi-carrier techniques that are used and proposed rely on similar radio access schemes and use of RF carriers which are within the same pass band of the transmitter of the wireless edge device.
Present radio techniques for a wireless edge device utilize discrete transmitters and receivers or a transceiver 401 for each radio access scheme and frequency band as depicted in FIG. 4. The receiver for the wireless edge device are wideband in nature facilitating mobile desense. The discrete transceiver 401 are connected to the wireless edge devices antenna 404 with the aid of a antenna selector system 403 which limits the selection of the frequency band and radio system utilized. The use of the antenna selector switch 403 also limits the potential for channel aggregation through diverse carriers operating in other frequency bands than the band selected with the antenna selector switch 403.
The use of discrete tranceivers 401 are being replaced with the use of Software defined radios 501 in FIG. 5 are seeing more use in wireless edge devices employing a tunable RF front end and potentially RF transmitters as well. The SDR approach while great has several limitations regarding RF channel aggregation. For instance the tunable filter 503, 506 or duplexer 504 as shown in FIG. 5 limits the ability of the mobile radio to use channel aggregation involving multiple radio bands. The configuration in FIG. 5 can be used for RF channel aggregation however the channels need to be close in RF proximity to each other, preferably adjacent and or alternate RF channels.
It is desired to have a wireless edge device that is capable of channel aggregation using multiple frequency bands and multiple radio access techniques at the same time. Additionally it is desirable to have a wireless access device utilize a multicarrier approach using different radio access points which can use different radio access techniques or different frequency bands at the same time. It is also desired to have a wireless access device be capable of multicarrier operation between multiple radio access points which may be operated by different wireless network operators.